A watershed moment for U.S. design is recalled in “Versailles ’73: American Runway Revolution.” Letting its interviewees describe a lavish fundraising event that brought together some of the biggest names in French and English fashion — as well as the entertainment and jet-set socialite worlds — ad exec Deborah Riley Draper’s film debut is plenty appealing in description. In execution, however, its near-exclusive reliance on vintage photos and latter-day talking heads grows monotonous, making its 90 minutes feel considerably longer. Opening on one Los Angeles screen Oct. 26, it should make an attractive cable item, ideally in trimmed form.

By the 1970s, Louis XIV’s fabulous Palace of Versailles was in desperate need of repair and restoration, whose costs were estimated at $60 million. Figuring that kind of money would be more easily found in America than Europe, organizers decided to mount a fundraising blowout that would be a competition between five prominent Gallic couture designers — the lofty names being Saint Laurent, Givenchy, Dior, Cardin and Ungaro — and five U.S. “counterparts” the Frenchmen would choose themselves. Bill Blass, Oscar de la Renta and Halston were considered no-brainers, but controversy attended the choice of sportswear-identified Anne Klein and Stephen Burrows, who was far less established, career-wise, than the others. (He’s also the only surviving designer interviewed here).

Selection of models (dwelt on too long here) was also heated, and once the enormous Yank contingent arrived in Paris, a tumultous time was had by all. Whether through malice, snobbery or sheer neglect, the French gave the Americans far less rehearsal time, keeping them waiting for hours in the Opera Royale without heat, food or even toilet paper while home-team forces lumbered though their paces at leisure. Soon the visiting designers were at each others’ throats, and their assigned stage director, Kay Thompson, quit in a huff, leaving everyone to fend for themselves.

But once the glitterati (including Princess Grace and Andy Warhol, natch) assembled for the actual event, all expectations were overturned. The first, Gallic segment of the program featured enormous sets, a 40-piece orchestra, and guest performers from Nureyev to Josephine Baker. It went on for 2 1/2 hours and many judged it a cumbersome, old-fashioned bore.

After a short intermission the Americans arrived, with no sets at all, just taped music and a bunch of mostly black models strutting their stuff (plus Liza Minnelli strutting hers). The blast of unpretentious high energy in both clothing and personalities, lasting under an hour, took viewers by storm; even the French press admitted the U.S. had triumphed. The complacent status of Paris as center of the fashion universe was shaken, for good.

It’s a fun story, but the docu really wears out its welcome after a time by letting a large cast of reminiscing models, assistants, et al. echo one another’s recollections. (One can only hear variations on “The audience went wild” so many times.) Also, after a few context-setting minutes, there’s very little archival film footage, just stills accompanied by yakking, and not enough background music to liven up the packaging. Result is like a party anecdote that delights until you realize the windy, detail-bogged teller may never shut up.